It is known to provide cargo container transport units, sometimes termed dollies, that are attachable to each end of a multi-ton cargo container. Examples of such units are shown in U.S. Pat. No. 2,968,490 to Baus, U.S. Pat. No. 3,131,950 to Weaver et al, U.S. Pat. No. 3,243,193 to Fulmer et al, and U.S. Pat. No. 3,386,747 to Watt. These patented devices are suitable for transporting containers on smooth surfaced highways, but they are not completely satisfactory for use on rough terrain because they are designed to have relatively small wheel travel and high rate suspension mechanisms. The present invention is directed to a wheeled transporter designed to include trailing arms for the ground-engaged wheels, and resilient spring means trained between the transporter frame and the rear end of each trailing arm; the transporter unit is designed for high wheel travel and low rate spring suspension, thus adapting itself for use on rough terrain.